Water dispensers for providing carbonated water are known.
EP0867219 describes a device for carbonating a liquid which comprises a container in which the liquid to be carbonated is contained, closable by means of a closure, a pressure-gas container containing the gas and an adapter which is sealingly connectable to the container. The adapter comprises means for releasing overpressure disposed therewithin.
U.S. Pat. No. 5,992,684 describes a water dispenser including a housing containing a water source and a water storage tank positioned above the water source. A water line connects the water source and the water storage tank, water being transferred from the source to the tank by a vacuum pump. A tap is coupled to the water storage tank. Optionally, a carbon dioxide injection system may be provided for producing carbonated water.
WO 2003/048027 describes a beverage dispensing apparatus for a residential refrigerator, including a drink supply canister holding a plurality of valve actuators, a water supplier for selectively supplying carbonated water and non-carbonated water, a gas supplier for supplying CO2 gas to carbonate the water, and a fluid director.
Other carbonated water dispensers are described in WO 2003/098136, EP1579906, WO 2006/092783 and U.S. Pat. No. 7,861,550.